Deflection compensation roll

Abstract

Headbox for a paper machine which discharges paper raw material onto a wire as a raw material jet from a slice which is supplied with the paper raw material. The headbox includes an orientation correcting arrangement for correcting a pulp fiber orientation by supplying the paper raw material as a correction flow to a single location in either a central portion of the slice or a plurality of locations other than end portions thereof. The paper raw material is one of extracted from a taper header in which paper raw material for a main flow is stored and extracted from a correction-only taper header in which paper raw material for correcting the pulp fiber orientation is stored. This abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

1. A headbox for a paper machine which discharges paper raw material onto a wire as a raw material jet from a slice supplied with the paper raw material, comprising:
 an orientation correcting arrangement for correcting a pulp fiber orientation by supplying the paper raw material as a correction flow to a single location in a central portion of the slice; and 
 said correction flow having a same flow direction as a main flow into the slice and being added at a beginning of the slice, 
 wherein the paper raw material is one of extracted from a taper header in which paper raw material for the main flow is stored and extracted from a correction-only taper header in which paper raw material for correcting the pulp fiber orientation is stored. 
 
     
     
       2. The headbox of  claim 1 , wherein the orientation correcting arrangement comprises a flow control valve. 
     
     
       3. The headbox of  claim 1 , further comprising another orientation correcting arrangement for correcting the pulp fiber orientation by supplying the paper raw material as a correction flow to two end portions of the slice. 
     
     
       4. The headbox of  claim 3 , wherein at least one of said orientation correcting arrangements comprises a plurality of paper thickness direction correcting arrangements overlapping in a direction of paper thickness for correcting the pulp fiber orientation in the paper thickness direction by supplying a correction flow. 
     
     
       5. The headbox of  claim 3 , wherein at least one of said orientation correcting arrangements comprises a plurality of paper thickness direction correcting arrangements overlapping in a direction of paper thickness for correcting the pulp fiber orientation in the paper thickness direction by supplying a correction flow via flow control valves. 
     
     
       6. The headbox of  claim 1 , further comprising another orientation correcting arrangement for correcting the pulp fiber orientation by supplying the paper raw material as a correction flow to two end portions of the slice via flow control valves. 
     
     
       7. The headbox of  claim 1 , wherein said orientation correcting arrangement utilizes concentration-controlled paper raw material. 
     
     
       8. The headbox of  claim 1 , wherein said orientation correcting arrangement utilizes concentration-controlled paper raw material when said correction flow flows to a location which is to become an end product in a direction of paper width. 
     
     
       9. The headbox of  claim 1 , wherein said orientation correcting arrangement comprises a flowmeter, a pipe and a flow control valve. 
     
     
       10. The headbox of  claim 9 , further comprising:
 a fiber orientation sensor for measuring the pulp fiber orientation; and 
 a control system for controlling said flow control valve on a basis of pulp fiber orientation data for manufactured paper obtained by said fiber orientation sensor, and data from said flowmeter. 
 
     
     
       11. The headbox of  claim 1 , wherein said orientation correcting arrangement comprises a flow pipe, a flow meter, a branch header and a flow control valve. 
     
     
       12. The headbox of  claim 1 , wherein the correction flow is oriented along the same direction as the main flow at an outlet of a turbulence generator. 
     
     
       13. The headbox of  claim 12 , wherein the paper raw material is extracted from the taper header in which paper raw material for the main flow is stored. 
     
     
       14. A headbox for a paper machine which discharges paper raw material onto a wire as a raw material jet from a slice supplied with the paper raw material, comprising:
 an orientation correcting arrangement for correcting a pulp fiber orientation by supplying the paper raw material as a correction flow to a plurality of locations on the slice that include two end portions thereof; and 
 said correction flow having a same flow direction as a main flow into the slice and being added at a beginning of the slice, 
 wherein the paper raw material is extracted from a correction-only taper header in which paper raw material for correcting the pulp fiber orientation is stored. 
 
     
     
       15. The headbox of  claim 14 , wherein the orientation correcting arrangement comprises a flow control valve. 
     
     
       16. The headbox of  claim 14 , further comprising another orientation correcting arrangement for correcting the pulp fiber orientation by supplying the paper raw material as a correction flow to two end portions of the slice. 
     
     
       17. The headbox of  claim 16 , wherein at least one of said orientation correcting arrangements comprises a plurality of paper thickness direction correcting arrangements overlapping in a direction of paper thickness for correcting the pulp fiber orientation in the paper thickness direction by supplying a correction flow. 
     
     
       18. The headbox of  claim 16 , wherein at least one of said orientation correcting arrangements comprises a plurality of paper thickness direction correcting arrangements overlapping in a direction of paper thickness for correcting the pulp fiber orientation in the paper thickness direction by supplying a correction flow via flow control valves. 
     
     
       19. The headbox of  claim 14 , further comprising another orientation correcting arrangement for correcting the pulp fiber orientation by supplying the paper raw material as a correction flow to two end portions of the slice via flow control valves. 
     
     
       20. The headbox of  claim 14 , wherein said orientation correcting arrangement utilizes concentration-controlled paper raw material. 
     
     
       21. The headbox of  claim 14 , wherein said orientation correcting arrangement utilizes concentration-controlled paper raw material when said correction flow flows to a location which is to become an end product in a direction of paper width. 
     
     
       22. The headbox of  claim 14 , wherein said orientation correcting arrangement comprises a flowmeter, a pipe and a flow control valve. 
     
     
       23. The headbox of  claim 22 , further comprising:
 a fiber orientation sensor for measuring the pulp fiber orientation; and 
 a control system for controlling said flow control valve on a basis of pulp fiber orientation data for manufactured paper obtained by said fiber orientation sensor, and data from said flowmeter. 
 
     
     
       24. The headbox of  claim 14 , wherein said orientation correcting arrangement comprises a flow pipe, a flow meter, a branch header and a flow control valve. 
     
     
       25. The headbox of  claim 14 , wherein the correction flow is oriented along the same direction as the main flow at an outlet of a turbulence generator. 
     
     
       26. The headbox of  claim 25 , wherein the paper raw material is extracted from the taper header in which paper raw material for the main flow is stored.